The present invention generally relates to fuel-fired water heaters and, in a preferred embodiment thereof, more particularly provides a gas-fired water heater having incorporated therein a specially designed plate-mounted removable bottom end burner and pilot assembly circumscribed by a flame arresting combustion air intake structure.
Gas-fired residential and commercial water heaters are generally formed to include a vertical cylindrical water storage tank with a gas burner disposed in a combustion chamber below the tank. The burner is supplied with a fuel gas through a gas supply line, and combustion air through one or more air inlet openings providing communication between ambient air and the interior of the combustion chamber.
Water heaters of this general type are extremely safe in operation. However, when gasoline or other flammable liquids are stored or used improperly in proximity to the water heater, there may exist a possibility of flammable vapors becoming entrained in the air intake of the water heater. It is theorized that such vapors might cause secondary combustion to occur within the confines of the water heater combustion chamber. It is accordingly possible for the resulting flame to propagate out of the combustion chamber into the ambient environment around the water heater as a result of following the intake path of the flammable vapor.
In conventionally constructed water heaters of this general type, a combustion chamber access door is typically provided in a vertical side wall portion of the water heater, with the burner and pilot gas supply lines extending horizontally through the access door into the combustion chamber and connected to their associated burner and pilot structures within the combustion chamber. This access door design can possibly provide a potential leakage path between the combustion chamber and the exterior of the water heater. Another potential leakage path is presented by the inlet passage used to flow ambient combustion air into the combustion chamber. For water heater designs focusing on controlling the entrance location of flammable vapors passing into the combustion chamber it would be desirable to provide a sealed access structure for the combustion chamber and to hinder the entrance of flammable vapors into the combustion chamber via an unintended combustion air inflow path. It is to these goals which the present invention is directed.